Page 3 of 3

Re: 5000w hybrid inverter for grid assisted solar charging

Posted: Mon May 20, 2019 1:12 pm
by ripple4
i used thick foil tape with acrylic adhesive to seal the gap i left between all the panels. i left about a 3/8" gap panel-panel, i only needed 1/32" of an inch to cover me from a CTE point of view. That said the glass does not seem to be sealed very well to the aluminum frame, and some drips come through. to stay grounded keep in mind The walls are 8' of screen so a robust wind will blow rain into the area a good ways, water always wins.

Image

Re: 5000w hybrid inverter for grid assisted solar charging

Posted: Mon Jun 10, 2019 8:12 am
by ripple4
Here is a idea how the PV combiner box finished up. I have two, two-pole DC breakers that switch PV+ and PV- to completely isolate PV from the circuit. then i have two parallel MOV packages for each PV+. On the panel layout, I ended up going with a 8-series arrangement instead of 6-series like i had planned before, which put the OCV at 362VDC. which is really close to my 240vAC MOV clamping voltage of 390VDC, so i stacked two MOVs in series to get a clamp voltage of 780vDC, which is fine for shunting lightning surges to ground and well below the 2000v rating of the PV wire i used. i'll have another ~580vDC MOV at the inverter inputs too. I ended up useing a MOV intended for a 120vAC and 240vAC in series to get 585vdc clamping, measured with a fluke 1000v insulation tester. the ac and dc rating of MOVs are different because the AC rating accounts for peak to peak voltage plus about 14%, where DC the RMS and peak are the same. typing that all out might make it seem like I may be a little overboard on surge protection, and that might be true.

https://ibb.co/dtpS8FH

Image

https://ibb.co/zXX929R

Image


there is also a labeled PV DC disconnect at arm level and outside facing for first responders to use, I have the breakers in the roof-mounter combiner box acting more like a switch for service in that box. in the event of a really good surge the MOVs will explode and need to be replaced.

https://ibb.co/Pcg8QBk

Image

Re: 5000w hybrid inverter for grid assisted solar charging

Posted: Tue Jun 11, 2019 8:42 am
by ripple4
Here is a idea what the 'DIY powerwall' for this solar porch is looking like. The AC and non-battery DC wiring is completed, all 10awg stranded thhn building wire, no lamp cord. the picture shows the purpose of the items i used. Right now, i think that i could direct solar charge the leaf, but it would switch to Edison power when a cloud came in front of the panels. one idea that worked well was how i did the cable tray on the bottom. they don't sell real cable trays at my local hardware store so i made one out of 6x 3/4" knock out handy-boxes, this is needed to keep the fan inlets free for airflow and the little conduit pieces are so close to the inverter and Xfer switch its little-finger safe. the load center is 220v only and has breakers for the EVSE, the 1-ton minisplit and a 7.5KVA 240/120 transformer, but those last two items are not bought yet, car charging comes first!

https://ibb.co/CmtZbw0

Image

The battery is still a work in progress, 286x of the the LiFePo4 battery cells came in, still waiting on a few more, the 120a BMS, and cell level fuses too. i was thinking that i would encase the battery in 4x large ammo cans, that way 3 of the ammo cans are a useful 12v 4s size and the 4th one which is 3s can hold the BMS. the plan is 32p 15s overall, 208AH capacity and 120amp max discharge.